Today's electronic devices (e.g., computers, digital cameras, video games, etc.) commonly contain electronic memory that is used to store data (e.g., files, pictures, etc.). Electronic memory comes in a variety of different types. One widely used type of electronic memory is Flash memory. Flash memory is a non-volatile memory (i.e., a memory that retains data when not powered) that provides for easy and fast data storage.
Flash memory stores information in memory cells having a floating gate separated from an overlying control gate and an underlying transistor channel region by an insulating layer. Because the floating gate is electrically isolated from the channel region by the insulating layer, charges placed on it are trapped. The trapped charges are indicative of a data state stored in the memory cell. For example, to read a flash memory cell the channel region's conductivity is tested (e.g., if it's conducting or insulating) by applying a voltage to the control gate. Since the channel region's conductivity is influenced by charges on the floating gate, the current flow through the channel region can be measured and used to reproduce the stored data state.